FR2486908A1 - METHOD AND DEVICE FOR PACKAGING OBJECTS USING EXTENDABLE FILM - Google Patents

Abstract

METHOD AND DEVICE FOR PACKAGING OBJECTS USING AN EXTENSIBLE FILM. TO SURROUND THE SHELLS FILLED WITH FRUITS OR VEGETABLES WITH A THIN AND EXTENDABLE FILM 18, THE LONGITUDINAL EDGES OF THE SAID FILM CAN BE TIGHTENED RIGIDLY BY SEVERAL MOVABLE CLAMPS 10 RUNNING ALONG THE SAID EDGES. EACH OF SAID CLAMPING CLAMPS 10 IS FIXED TO A DOUBLE ENDLESS CHAIN 22 AND HELD IN ITS CLAMPING POSITION BY A BACKING PLATE 17. A SECTIONING BLADE 48, WHICH IS USED TO CUT A SHEET FROM THE FILM, IS LOCATED IN A POSITION SUCH THAT THE SEPARATION TAKES PLACE AT A POINT WHERE THE TWO PARTS OF THE FILM, UPSTREAM AND DOWNSTREAM, ARE BOTH TIGHTENED BY CLAMPS 10. THIS MAKES A LARGE MEASURE OF TAKING UP THE FILM WHICH UNDELINS WITH ONE FOOD CYLINDER.

Description

The subject of the invention is a process for packaging dtob

  jets, in particular of fruit, vegetables or meat, the said ob-

  jets in a shell-shaped container, while a long film is called from a feed cylinder with a cut sheet, that the sheet

  cut is stretched from the top over the container

  fold of said objects and that finally, the edges of said sheet are folded on the underside of the container where they are fixed. The invention also relates to a device for packaging articles contained in a shell-shaped container, in particular fruits, vegetables or meat, using an extensible film whose leaves are cut, by means of 'a cutting mechanism, in a long strip, as well as clamping mechanisms that grip

  the edges of said sheet and means for wrapping

  per container garnished with this sheet.

  The process of using foils is known.

  stretchers for packing fruits and vegetables

  wind in a shell-shaped container. These leaves, de-

  cut to the desired length in a film called a

  feeding cylinder, are stretched from above to the shell.

  the full. Then, the latter is raised by a plateau

  lifter, the edges of the sheet are folded onto the

  Upper shell and glued together by thermal effect.

  For this purpose, the extensible film, which is made of a flexible plastic material, must be extremely thin, in order to be able to adapt it to the objects to be packaged when these

  have an irregular surface, without producing points of contact

  pressure on packaged goods, some of which,

  -the fruits for example, - are particularly sensitive.

  On the other hand, the use of these films in packaging machines is linked to difficulties as a result of the resilience of said films, their considerable extensibility and their deformability, hence important mechanical means for

  avoid both tearing and thinning this thin film

to make folds.

  The problem to be solved by the invention consists in developing

  to develop a method and a device of the type considered

  to simplify handling of the thin film during

2 2486908

  packaging, while making the machine less prone to

  storage. The method according to the invention, by means of which this problem is solved, consists of grasping the two lateral edges, in the direction of travel, of the film between a plurality of grippers.

  spaced, mobile, which intermittently convey the

  said film, the sectioning of the sheet intervening in this area only after the seizure of the lateral edges by a

clamp at least on each side.

  As to the device according to the invention, it comprises several

  clamps placed at a distance from each other, on either side of the film,

  pliers are fixed on endless chains, while

  that of support comes, in the tightening zone, to solicit towards the

  down said tongs and can fade to free them.

  The method according to the invention and the corresponding device

  give the assurance that the leaf is always held and stretched laterally, even when the leaf has been cut

of the film.

  In this way, it is no longer necessary to seize the pel-

  again after cutting a sheet to be able to pull the next sheet, since the film, already

  tight, can be pulled simply by the clamps.

  In addition, the adjustment of the machine to change dimensions as well as the tightening and loosening of the film become

particularly simple.

  An exemplary embodiment of the invention, without any

  is described hereinafter and illustrated in the accompanying drawings, in which: FIG. 1 is a side view, partially in section, of

  clamping members of the film, with the driving members

  and adjustment, Fig. 2 is a plan view of the collets, sectioning blade and backing plate, FIG. 3 is a horizontal sectional view of the device of

  adjustment allowing the use of films of different widths

  fers, and FIG. 4 is a perspective view of the area

  introducing the film into a collet.

  A film of extensible material is brought to a packing station o objects placed in a shell of cardboard or the like, for example fruit, vegetables or

  meat, - are covered with a leaf cut from the

  called film. Then, the edges of the sheet thus cut are folded under the bottom of the shell where they are fixed by

  thermal effect. The film is unrolled from a food cylinder

  tion and cut to a specified length. This film

  18 is grasped laterally, according to the direction of advancement,

  by its two edges 18a using clamps 10 which

  they are fixed on shades 22, as shown in FIG. 1.

  Each of these clamps 10 is arranged on a pair of chains 22, said clamps being spaced along the chains. Each of the endless chains 22 thus passes laterally to an edge 18a of the film 18 and rotates around a pulley, or wheel, at each horizontal shaft, such that between each pair of chain wheels 20 are an upper strand and

  a lower strand of the chain, both being rectilinear.

  The drive of the wheels Aàchaines is ensured intermittently, in synchronism with the rate of operation of the machine

to pack.

  the upper part 11 of each of these clamps

  10 can pivot relative to its lower part 12 by means of a pivot 14. To block the film 18 between the upper and lower jaws 13 of a clamp 10, the upper part 11 of the latter is supported, with the aid of FIG. a roller 15, on the film by a support plate 17. The roller 15 is held in the upper part 11 by a threaded shaft 16 on which it can rotate. This axis 16 is perpendicular to the running direction of the film 18, so that the roller 15 can roll on the support plate 17 parallel to the cat 22. However, the roller 15 can also be replaced by a support

  directly from the upper part 11 against the support plate 17.

  In this case, to reduce friction, said upper portion

  11 is made of plastic. Fixing the lower part 12 of the clamps 10 on the double chain!

  22 is made using dowels 24, corneal

  25 and screw 25. Since the return pulleys 20 of the chains are double as the latter, the guide of the clamps 10 is very sfr. At the opposite side edge of the film 18, there are clamps, chains and identical wheels & chains. However, for the sake of clarity, only one

  is described below, the other side having a configuration

identical ration.

  The support plate 17 is held in its lower position by means of two eccentric elements 19 situated at the opposite ends,

  squeezing and blocking the film 18 placed between the two

  Furthermore, the clamping effect can be eliminated by rotating the eccentrics 19 for

  bring in their loosened position. This operation is

  kills when the shell under the film 18, and

  which contains the goods to be packaged, is lifted vertically

  by a lifting table and said film must be released to obtain the desired tension thereof. It is

  rational to assign to the clamps on both sides of the pel-

  12 separate support plates 17, which can be operated by

  eccentric 19 distinct from each other. We can thus

  berate the two edges 18a of the film A at different times.

  ent. However, the support plates 17 can be clamped against the clamps 10 or peeled off by means other than the eccentrics 19, for example by cam discs, electromagnets, hydraulic or pneumatic assemblies.

of cylinders and pistons.

  For cutting a sheet of the film 18, a cutting blade 48 is disposed perpendicular to the running direction of the film. This blade is lowered

  between two adjacent clips 10, thus cutting the film 18.

  For the sectioning operation, the entratnement and the command

  are made using cam discs. Below the pel-

  12, there is preferably a fixed opposing blade conjugate with the blade 48, but not shown in the drawing. The

  arrangement of the cutting blade 48 is such that

  worth the scroll direction of the film, it is

  ve downstream of the first or second pair of clamps which clamp the film 18 on either side, but upstream of the plate

  support 17, as shown in fig.2.

  To allow the use of films of different widths

  verses, the transverse distance between the chain wheels 20,

  therefore that separating the clamps 10 is changeable.

  The shift is effected, as indicated in FIG. 1, using a hand wheel 40, secured in rotation with a threaded rod 38. This threaded rod 38 is coaxial with a hollow shaft 34 which it crossbar, engaging a captive nut 44, which is connected, by fixing screws 46, to the hub 26 of the chain wheels 20. A bearing ring 28 is screwed onto one of the double chain wheels 20 with interposition of A spacer ring 27. This ring 28 contains two bearings 30, bearing on inner rings 32 slidable on the shaft 34 in the axial direction. On the other hand, the shaft 34 is supported on a fixed part of the frame of the machine by means of one or more bearings 36. By acting on the operating wheel 40, the lacquer is located at Outside the casing 42 of the mechanism, the double chain wheel 20 can be shifted along its axis. A symmetrical double wheel, located on the other edge of the film, is

  axially offset by reverse threading of the same rod file.

  38, but in the opposite direction, such that the steering wheel rotation 40 drives in one direction, reducing the distance between the double-chain wheels 20 on either side of the film, the increase in distance in the opposite direction

  FIG. 3 illustrates a variant of the device according to the invention.

  invention, consisting of a motor mechanism for changing the transverse distance between the two pairs of chains 22 which carry the clamps. The two hubs 26, 26a of the chain wheels 20 are mounted on the same shaft 34, rotatable in the frame 37 of the machine. Between each of the hubs 26 and 26a and their common shaft 34 is a key 39 which coulii

  easily in an axial groove 41 of the shaft 34.

  threaded thread 55, parallel to the shaft 34 and arranged at a certain

  distance from it, can also turn in the frame 37 of the machine and is driven by an electric motor 57. One half of this threaded spindle 55 carries a right-hand thread 55a, the other half a left-hand thread 55b . In one

  halves is engaged a support 59, in the other a sup-

  port 61 parallel. The support 59 carries the hub 26 through the

  The support 61 carries the hub 26a via the ball bearing 65. The supports 59 and 61 each carry, on the other hand, a hub situated outside the limits of the drawing. hence the training. When the motor 57 is activated, the two keys 26, 26a therefore move in the respective directions of the arrows E and F. In the event of reversal of the motor direction, said hubs 26, 26a are shifted in the opposite direction. It is thus possible to vary the transverse distance between the clips 10

  in order to adapt the device to films of different widths

  rents, using a motor device. 4 shows that the pivoting upper part 11 of each clamp 10, previously in the open position due to its own weight, arrives, by going up along the chain wheels 20, in contact with a curved ramp 62 who maintains the

  clip 10 in this open position until it

  bank to the trajectory, generally rectilinear, of the film

  on arrival, said film 18 being usually transparent

  annuity. The clamping force of the clamps 10 on the edge 18a of the film is exerted only under the action of the support plate 17a which follows the ramp 62, then the plate 17. To facilitate the " 1enfilagen of the film 18 in case of change of the latter, a lever 66, pivotable about an axis

  vertical 68, cooperates with the first support plate 17a. This

  he is maneuvered using a spherical handle 70.

  to toggle the first plate 17a up and down, the

  upper part 11 of each clamp 10 can then be

  raised by hand to engage the film. When the

  1 is grasped by at least one pair of clamps, the first plate 17ae and the pivoting lever 66 are brought back to their position in FIG. 4, so that the clamps 10 exert on the film 18 a clamping device allowing shoot the film

  called from its feed cylinder.

Claims (8)

  1.- Method for packaging objects, especially fruit,   of vegetables or meat, the said objects being in a   shell-shaped container, while a film of great length is called from a feed cylinder, a film is cut off, the latter is stretched from above over the container filled with said articles and that finally the edges of said sheet are folded on the underside of the container where they are fixed, characterized in that the   two side edges of said film, in the direction of the scroll   of it, are seized between several collets   (10) spaced apart from each other, which in turn propel   termittence said film, sectioning a sheet   intervening in this zone only after the seizure of the   by a clamp at least on each side.   2.- Device for packaging objects, in particular fruit, vegetables or meat, contained in a shell-shaped container, using a film of extensible material whose leaves are cut from a long strip   by means of a sectioning mechanism, as well as   clamping devices which grip the edges of said film and means for wrapping the container therein   sheet, device characterized in that the mechanisms of   rage comprise several clamps (10), spaced apart from each other, on both sides of the film, said clamps being fixed on endless chains (22) along the two edges of the film (18), while a releasable support plate (17)   to loosen the clamps, presses against them in the clamping area.   3.- Device according to claim 2, characterized in that, along each of the two edges (18a) of the film in the direction of travel of the latter, runs a chain.   double (20) to which the lower parts are rigidly   (12) of the collets (10) at a distance from each other, while the upper parts (11)   pliers, which can pivot relative to said parts   (12) cooperate with their support plate (17) which has an adjustable height (Fig.1).   4.- Device according to one of claims 2 or 3,   characterized in that adjustment members (38, 40, 44) are 2-486908   to vary the distance between the double chains (22)   on both sides of the film, thus allowing the adaptation   distance from the chains, ie clamps (10)   at different widths of the film (Fig.1, 3).   5.- Device according to claim 4, characterized in that a threaded rod (38) passes through at least one of the hubs (26) of the impeller wheels (20) so as to allow the offset   said pulleys (20) in the axial direction (Fig.1).   6.- Device according to one of claims 2 to 5,   characterized in that, in the area of introduction of the film into the clips, a curved ramp (62), located upstream of a first support plate (17a), guides the upper portions   (11) clamps (10) (Fig.4).   7.- Device according to one of claims 2 & 6,   characterized in that a disconnecting member (48) of the film   It is located at a point in the action zone of the   killed between the first or the second pair of clamps (10) which effectively grip the film, - following the direction of scrolling of the film, - and the support plates (17, 17a) (Fig.2) 8.- Device according to claim 4, characterized in that the hubs (26, 26a) which carry the chain wheels (20) are axially shiftable on a shaft and that they are, moreover, integral with the movement of a threaded spindle (55). ), which can be driven by an electric motor (57) which rotates selectively in one direction or the other (Fig.3) *   9.- Device according to one of claims 1 to 8,   characterized in that the support plates, on either side of the film, are double (17, 17a), the upstream plate (17a) in the direction of travel of the film being pivotable by   manual handling to simplify the exchange of the (Fig.4).